[CLASSIFICATION AND DIAGNOSIS OF AXIAL SPONDYLOARTHRITIDES – HISTORY, PRESENT STATE, AND PERSPECTIVES].

Spondyloarthritis (SpA) is a group of inflammatory rheumatic diseases that share some common genetic, clinical, serological, radiological, and prognostic features. Since the early 1960s, several classification criteria for SpA have been proposed, and some of them were also used for diagnostic purposes. The ASAS international group of experts established a set of classification criteria for SpA, dividing them into axial or peripheral, according to predominant involvement. The paradigmatic entity of axial SpA is ankylosing spondylitis, which is diagnosed in clinical practice with significant delay. Therefore the ASAS classification introduced the term “non-radiographic axial SpA”, which refers to changes in the sacroiliac joints seen on MRI, but not on radiograph. Although the ASAS classification has been widely accepted in the professional community, recently initiatives were raised suggesting changes and aiming at improvements. In this paper these objections are discussed, as well as the responses of experts who consider that these changes are not necessary.